Chancellor Angela Merkel and her challenger in Germany’s upcoming election said Sunday they wouldn’t participate in military action against Syria.

Merkel said that “Germany will not participate” in a military strike as she faced center-left rival Peer Steinbrueck during a televised debate Sunday before the Sept. 22 vote.

Merkel says that there needs to be “a collective answer by the U.N.” to the use of chemical weapons in Syria. She says she is “very glad that we have a few days” to revive efforts to secure U.N. action — a reference to President Barack Obama’s decision to seek authorization from Congress for military action.

Steinbrueck said he wouldn’t participate in military action as chancellor and would “greatly regret it” if the U.S. strikes alone without an international mandate.

The challenger also insisted that Merkel’s government still hasn’t cleared up “what damage arose” to Germany as a result of surveillance by the U.S. National Security Agency — an issue that so far has failed to shift voters in polls.

“On German soil, we have no reason at the moment to say that the NSA spies widely on Germans,” Merkel said.

Recent surveys have given Merkel’s conservative bloc a large lead over Steinbrueck’s Social Democrats and suggested that her current center-right coalition can hope to win re-election.

Steinbrueck was Merkel’s finance minister in her 2005-09 “grand coalition” of right and left — an experience that both insist they don’t want to repeat, but could emerge if the election were to be indecisive.